Bioengineering is now being used to create a renewable fuel alternative to petroleum diesel. But unlike biodiesel, which is made from vegetable oil, this fuel is created by microorganisms.

Photo: Adam Bayley/KQED

Scientists at Emeryville-based Amyris, known for their work with the anti-malarial drug Artemisinin, have devised a process for synthesizing hydrocarbons similar to those found in regular diesel.

The first vehicle to run on this renewable fuel, an Audi Q7, premiered Thursday at Infineon Raceway in Sonoma. While the fuel won’t be available at your local filling station anytime soon, it does represent a unique step in the expanding renewables’ market.

Creating biodiesel is a chemical process that transforms vegetable oil into usable fuel for diesel vehicles. It’s made through a chemical reaction in which plant oils, methanol and lye are mixed and react to form glycerol (i.e. soaps) and biodiesel.

The process of creating diesel from sugar and yeast is slightly more complex. Instead of a single chemical reaction, this new process must be biologically engineered by changing the genetic code of the yeast — to create a different molecule. Simply put, it’s hijacked and told to make something different. The process is similar to the way insulin in a lab is created for the treatment of diabetes. Before scientists could manipulate bacteria, they extracted insulin from pigs and cows.

But Amyris scientists are doing something much more difficult than just changing the yeast’s genetic code. They also change the environment in which yeast grow and live. These changes reprogram the way the micro-organism metabolizes and processes chemicals. In this case, the genetic modifications allow yeast to eat sugar and excrete diesel fuel.

So is this the answer to our energy problems? Not yet. The sensitive and tedious process requires hours of research and experimentation. Scaling it enough to meet U.S. energy demand would require a considerable investment, as well as perfecting the laboratory science for commercial use.